Commutator separator undercutting machine



Nov. 21, 1939. L. E. POOLE 2.180,

COMMUTATOR SEPARATOR UNDERCUTTING MACHINE 7 Filed April 12 1937 lo Sheets-Sheet l 2&0 1

N v- 21; 1939. L. s. POOLE COMMUI 'ATOR SEPARATOR UNDERCUTTING MACHINE 1O Shets-Sheet 2v Filed April 12, 1957 NOV. 21, 1939. POOLE COMMUTATOR SEPARATOR UNDERCUTTING MACHINE Filed April 12, 1937 10 Sheets-Sheet 3 Nov. 21, 1939. E. POOLE 2,180,771

GOMMUTATOR SEPARATOR UNDERCUTTING MACHINE Filed April 12, 1937 10 Sheets-Sheet 4 Q 0 G7 Z/8 30 o "222 c 44 24 o ,2/4

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Nov. 21, 1939; L EQPOOLE 2,180,771

COMMUTATOR SEPARATOR UNDERCUTTING MACHINE Filed April 12, 1937 10 Sheets-Sheet 5 Nov. 21, 1939. E,'P 2,180,771

COMMUTATOR SEPARATOR UNDERCUTTING MACHINE Filed April 12, 1957 10 Sheets-Sheet 6 m wuw NW M L E,

Nov. 21, 1939. LE. POOLE COMMUTATOR SEPARATOR UNDERCUTTING MACHINE Filed April 12 1937 10 Sheets-Sheet 7 w mm Mum

L. E. POOLE COMMUTATOR SEPARATOR UNDERCUTTING MACHINE Noy. 21, 1939.

Fiied April 12, 1957 10 Sheets-Sheet 8 L. E. POOLE COMMUTA'LOR SEPARATOR UNDERCUTTING MACHINE Nov. 21, 1939.

Filed April 12, 1937 l0 Sheets-Sheet 9 Nov. 21, 1939. E. POOLE 2180,771

' COMMU'IATOR SEPARATOR UNDERCUTTING MACHINE I Filed April 12, 1937 10 Sheets-Sheet l0 l lh A Qd h5o m mum \j m ham mom A mm NNN k$QmU .AN kfiuwsu min Vl- QQ MIN g m M whx EESJI RN mwn W Patented Nov. 21, 1939 A UNETE .STA'E'ES COMMUTATOR SEPARATOR UNDERCUT TING MACHINE Lora E. Poole, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 12, 1937, Serial No. 136,464

23 Claims.

This invention relates to a machine for under-' 5 ated automatically are providedwith commutator indexing devices which turn the commutator, previous to each undercutting operation, equiangular distances, and therefore operate successfully only when the mica separators are spaced equi-angular distances. If it happens that, due to variations in thickness of the commutator bars and/or the mica separators or to variations in manufacture, the latter are not exactly spaced 16 equi-angular distances apart, an attempt is made tator on a machine using any of the automatic indexing mechanisms heretofore known the result is that, frequently, the cutter is not located exactly in alignment with the mica separators and therefore only a partial width of a mica separator is undercut while the remaining width thereof remains flush with the periphery of an adjacent commutator bar. These variations of spacing the mica separators must therefore be met by manually indexing the commutator to bring the mica separators into exactalignment with the cutter, an operation which is slow and, hence, increases cost of manufacture.

It is the primary aim and objectof the present invention to, provide a machine which automatically undercuts the mica separators of a commutator rapidly and accurately. It is more particularly an object of the present invention to incorporate in the machine an automatically performing mechanism which rapidly and accurately aligns successive mica separators of a commutator with the cutter.

These and other objects of the present invention are accomplished by providing a table which is reciprocable relative to a rotary. cutter and on which arotary chuck for a commutator is mounted. This chuck includes a ratchet turned by a pawl which is actuated by a stationary cam during the latter part of one reciprocation of the table, whereby the chucked commutator is slightly turned sufficiently to disalign the last undercut mica separator from the cutter. A suitable power drive, including a normally disconnected friction clutch, is adapted to continue the indexing of the commutator until the next mica separator is in alignment with the cutter. Clutch engagement is madeby a solenoid, the energizing circuit of which can be closed onlythrough a conductive commutator bar. Therefore, a relatively stationary arm is provided with two contact points to undercut the mica separators of such a commu-' which are part of the solenoid circuit and spaced apart longitudinally of the commutator. These points simultaneously contact either a mica separator or aconductive bar of the commutator, and close the solenoid circuit when the latter contact is established. Their location is such relative to the cutter that they contact that mica separator only which is in operative alignment with the cutter. Consequently, upon disalignment of the last undercut mica separator from the cutter by the earlier mentioned cam operated ratchet mechanism, the energizing circuit for the solenoid is closed across the points by the contacted conductive commutator bar. The energized solenoid causes engagement-f the friction clutch and corresponding rotation of the commutator. The points remain in contact with the moving commutator bar and maintain the solenoid circuit closed until the next mica separator moves into contact with the points, whereupon the solenoid circuit is interrupted and the friction clutch disconnected. This next separator is now in perfect alignment'with the cutter due to theexplained coordinated location of the contact points and the cutter. The point carrying arm is pivotally mounted, and provision is made to let thepoints descend upon-the commutator immediately after the latter comes to rest upon a complete reciprocation of the table, thus protecting the contact points against unnecessary wear, yet allowing no idle time to pass between a completed reciprocation of the commutator and the indexing thereof. In order to start the table on its next reciprocation immediately after a concluded indexing operation upon-the commutator, use is made of an electric control system which causes the energizing circuit of another solenoid to be closed immediately after the energizing circuit of the indexing solenoid is opened. This othersolenoid is adapted to connect a normally disconnected one revolution clutch which establishes a driving connection between a power drive and a crank mechanism for reciprocating the table once during one revolution of said clutch. Suitable mechanism is also provided for stopping the machine automatically when all mica separators of a commutator are undercut.

Further objects and advantages of the present invention will beapparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a fragmentary front elevation ofa machine embodying the present invention.

Fig. 2 is a plan view of the machine.

Fig. 2a is an end elevational view of a commutator.

Fig. 3 is a fragmentary perspective view of part of the machine as viewed in the direction of arrow 3 in Fig. 1.

Fig. 4 is another fragmentary perspective view of one end of the machine as viewed in the direction of arrow 4 in Fig. 1.

Figs. 5 and 6 are enlarged fragmentary perspective views of details of the machine in different positions of operation.

Fig. '7 is a fragmentary elevational view of the machine. Part of the machine is shown in section which is taken substantially on the line 'I'I of Fig. 2.

Fig. 8 is a fragmentary rear elevation of part of the machine.

Fig. 9 is a section taken substantially on the line 0-9 of Fig. 8.

Fig. 10 is a detail view of the cutter-carrying frame.

Fig. 11 is a section taken on the line II--I I of Fig. 10.

Fig. 12 is a fragmentary section taken on the line l2 I2 of Fig. 2.

Fig. 13 is a section similar to Fig. 12, showing certain elements thereof in a different position of operation, however.

Fig. 14 is a fragmentary section taken substantially on the line l4--l4 of Fig, 2.

Figs. 15 and 16 are diagrammatic perspectives, showing the cooperation between certain structures of the machine.

Fig. 1'7 is a wiring diagram of the electrical control system of the machine.

The present machine is adapted to undercut the mica separators 20 of a commutator 22 in the manner illustrated at 24 in Fig. 2a.

The commutator is already assembled with an armature 26 when operated upon by the present machine. The insulating mica separators 20 are more particularly interposed between conductive commutator bars 28 which are usually of copper.

The present machine is so constructed that all mica separators 20 of a commutator 22 will be undercut automatically once the machine is started, and an automatic stop becomes effective when all mica separators of the commutator are undercut.

Y Referring more particularly to Figs. 1, 2 and 7,

the present machine comprises a machine frame 30 which has guideways 32 for a reciprocable table 34. Some of the operating mechanisms of the present machine are carried by the table 34,

while other operating mechanisms of the ma- Idle chuck A1 Referring more particularly to Figs. 2 and 7, the table 34 is provided with guideways to which a saddle 42 maybe clamped by the handle 44 in any adjusted position therein. This saddle 42 comprises a cylinder 46 which is closed by end covers 48 and 50 and receives a single-acting piston 52, a rod 54 of which carries a ball bearing 56 that journals a center 58 for one end of a shaft 60 of an armature 26. Interposed between the end cover 48 and the piston 52 is a compression spring 62 which normally urges said piston into the right end position illustrated in Fig. 7. The end cover 50 is provided with a duct 64 which provides communication between the active cylinder side 65 and a conduit 66, connected with a valve 68 which is mounted on the machine frame 30. This valve, which may be of any suitable type, is in permanent communication with a suitable source of fluid pressure (not shown) through a conduit I0, and includes a valve stem I2 which assumes the illustrated, raised position in Fig. 1 when the valve is normally closed. Pivoted at I4 to suitable lugs I6 is an arm 18 which is connected through a link 82 with a foot pedal 86, suitably pivoted at 88 to the machine frame 30. The valve stem 12 is depressed by the arm 18 upon depression of the foot pedal 86, whereupon fiuid pressure is admitted through the valve 68 and through conduit 66 to the active cylinder side 65, thereby forcing the piston 52 to the left as viewed in Fig. 7 against the compression of spring 62. The released foot pedal 86 is returned to the illustrated position in Fig. 1 by a spring 90 which forces the pedal into engagement with a stop 92, thereby permitting the valve stem I2 to be returned to its normal valve closing position in which a vent passage (not shown) of the valve 68 permits the fluid pressure in cylinder 43 to escape so that the piston 52 may advance into the illustrated position in Fig. 7 under the compression of spring 62.

' Driving chuck A2 Also mounted on the table 34 is a bracket I00 which provides a cylindrical bore I02, containing the driven clutch element I08 and the sleeve II4 in place and more particularly in engagement with the thrust bearings I04, as appears readily from Fig. 7. It can now be understood that the driving chuck or center II6 for the armature shaft 60 is freely rotatable only, whereas the opposite center or idle chuck 58 is freely rotatable and movable longitudinally. Suitable armature locating bars I20 are adjustably mounted on brackets I22 on top of the table 34, and serve for the ready alignment of the shaft of an armature with the chuck centers 58, H6 before the shaft is properly received thereby.

Indexing mechanism B Referring particularly to Figs. 2, 4, 7 to 9, inelusive, 15 and 16, the earlier described driving element II 2 of the friction clutch H0 is splined at I 30 to a hollow shaft I32 which is journaled in bushings I34 of a housing I 36, mounted on the table 34. gear I 33 which is in permanent mesh with another gear I40, carried by a slow shaft I42 of a reduction gearing I44 that is driven by an electric motor M6. The driving clutch element H2 is provided with a plate I48 in alignment with a rod I50 which is received by the hollow shaft I32. The other end of rod I50 is in alignment with an armature I52 of a solenoid I54, the energizing circuit of which can only be closed Mounted on the shaft I32 is a throughone of thecopper. bars 2t} of a commuficient at present to state that this circuit includes two contact points I56 whichwill have to be bridged by a conductive commutator bar 28 in order to close said circuit. When the machine is in operation and the contact points I56 are in engagement with one of the conductive commutator bars 28, .the solenoid circuit is closedand the armature I52 thereof moves to-cause engage- :ment of the friction clutch -I II] and corresponding rotation of the chucked armature. The indexing of the armature amounts each time to the angular distance between successive mica separators 29, and successive mica separators will thus be moved into alignment with a rotary cutter I58, as canbe best understood'from Figs. 2, and 16. Thecontact points I56 are more particularly in alignment with the cutter I58 so that they simultaneously contactthat mica-separator whichis in operative alignment with said cutter. The contact points I56 are carried by an arm I611 which is journal-ed on'a stub shaft I62, depending from a frame I 64 on top of the machine frame 38. It is obvious from the preceding that the solenoid I54 is not energized and the clutch Mil is disengaged-after a concluded undercuttingoperation since the contact points I56 are then in alignment with an insulating mica separator as. In order to close the solenoid circuit, the-chucked armature will have to be turned slightly so as to bring a conductive commutator bar 28 into alignment withthe contact points I56 Means for slightly turning the commutator This slight turning'of thearmature 15 2000111- plished by mechanical means during the latter part of one complete reciprocation of the table 34. The driven clutch. element I03 is provided with ratchet teeth I'Ifi with which cooperates pawl H2, pivotallym-ounted at Il' i to .abar. I'Iii which is guided for linear movement in suitable ways N8 of the bracketiti). Bar H6 carries a roller I85! which is normally urged against a I34 on the frame its by a compression spring I86. Cam ISfi has a rising lobe I88 which is adapted tocooperate withthe roller I82 in mov ing the bar-I15 against the compression-of spring I85 and slightly turn .the driven clutch, element I88 in indexing direction through intermediation of the pawl I12 and the ratchet teeth ill). The cam lobe .588 is so located that the just mentioned slight turn of the driven clutch element takes place during the latter of acomplete reciprocation and just before the table ii comes to rest in the home position illustrated in Fig. 2, in which the cutter I53 is remote from the con1- mutator 22 and permits rotation of the latter without interfering with the'cutter. When the armature has thus been slightly turned, the contact points I56 are then in alignmentwith econductive commutator bar which connects these contact points, therebyclosing the solenoid circuit and causing clutch engagement. This ;condi-.

tion is illustrated. diagrammatically in Figs. 15

and 16. More particularlvFig. 15 shows the end of the slight turn of the armature as caused by the stationary cam ISt. It will be noted in Fig. 15 that the clutch H8 is still disconnected, however, the contactpoints I56 will at the next mo.- ment close the solenoid circuit acrossjthe conductive commutator bar 28a and cause clutch engagement in the manner illustrated in Fig. 16.

Of course, the solenoid circuit remains closed while the contact points I rest on the moving commutator bar 23a, and is. opened when the contact points come to rest on the mica separator the which is to be undercut next. This insulating mica separator, being then the only connection between the contact points E55, causes opening of the solenoid circuit and immediate disconnectionof the friction clutch I I!) under the force of a spring-urged plunger I539. To prevent overtravel of the driven clutch element Hi8, a yielding brake Ifiii restrains rotation of this clutch element in the manner shown in 3. To-avoid interference between the contact points i55 and the while the latter reciprocates the point carrying arm IfiI! is cammed out of the path of movement of said armature a roller I92 which is mounted on top of the bracket tilt. Thus.- when the table 3! moves in a direction in which the commutator approaches the cutter I58, the arm Kit is rocked clockwise as viewed in Figs. 5, 6 and 'Z. The arm it'll will rock back toward the commutator upon movement of the table inthe opposite direction, i. e. into the home position shown in Figs. 2 and 7. More particularly, the roller 692 is so located that it will permit descent of the contact points Iiiii into contact with the corn-- mutator at the end of a complete reciprocation ofthe slide, i. c. after the slight turn of the commutator has already been accomplished by the cam I86. The contact points it; will, corrsequently, come to rest upon a moving commutator bar and the sliding engagement .therecee tween extends only over a distance which is less than the thickness of the commutator bar. Thus, the comparatively fine points Hit are not worn excessively and will perform satisfactorily for a long time before requiring resharpening.

Table operating mechanism C 'Referring to Figs. 1, 4, 8 and 9, the table 3 3 is connected through ali'nk 2% with a crank pin 2132 which isadjustably mounted ina radial slot 264 of a disc 206 on a stub shaft 298, suitably journaled in a sleeve 2) of a bracket 2I2 which is mounted on the machine frame 35. Journaled on the stub shaft 263 isa gear ZI-G which is in permanent mesh with a smaller gear 228 on a shaft 229, suitably journalecl ina bearing bracket 222 and connected to a slow shaft 223 of a reduction gearing 225 which is driven by. an electric motor 226. Gear 266, which is continuouofly driven whenthe machine is in operation, carries a clutch element v22$, a companion element 233 until a beveled notch 244 of clutch element 230 is out of alignment with the beveled point 242. The beveled point 242 registers with the beveled notch 244 (Fig. 4) only when the clutch is disengaged. The clutch is engaged in any other angular position of the element 230 in which a bottom surface 246 thereof rides on top of the beveled point 242. Thus, only a short energization of the solenoid 238 is required to cause clutch engagement through one complete revolution of the same, i. e. until the beveled notch 244 realigns and registers with the beveled point 242. Suitable electrical control provisions, to be described later, effect the closing of the energizing circuit for the solenoid 238 immediately after the opening of the energizing circuit for the indexing solenoid I54, i. e. immediately upon alignment of a mica separator with the cutter I58.

Cutter D Referring more particularly to Figs. 1, 2, 10 and 11, the cutter I58 is mounted on a spindle 250 which is journaled in ball bearings 252 of a quill 254, slidable horizontally in a frame 258 which is in turn vertically slidable in suitable guideways 258 of the frame I64, and is secured in adjusted position therein by suitable screws 288. The quill 254 is provided with rack teeth 282 which mesh with a gear 264 on a spindle 268 which is journaled in the frame 256 and provided with a hand knob 268 for turning the gear 264, thereby moving the quill 254 so as to adjust the cutter in perfect alignment with a mica separator which is disposed in a vertical plane. Suitable means (not shown) secure the quill 254 to the frame 288 in properly adjusted position. The other end of the spindle 250 carries a pulley 270 which is driven by a larger pulley 272 of an electric motor 2'10 through a belt 216. Motor 274 is pivotally mounted at 278 to the machine frame and is otherwise suspended on the belt 2% which is tensioned by rocking the motor 274 counterclockwise as viewed in Fig. 1 by means of a screw and nut 280, 282.

Control mechanism E Referring more particularly to the wiring diagram in Fig. 1'7, the electrical control of the present machine comprises four circuits: a control circuit I, another control circuit II, the energizing circuit III for the table solenoid 238, and the energizing circuit IV for the indexing solenoid I54. It is the function of the control circuits I and II alternately to close the solenoid circuits III and IV by means of a single pole double-throw switch 290 which is magnetically controlled. The solenoid circuits III and IV and the control circuit II operate preferably with 110 volts D. C., whereas the control circuit I operates with a lower voltage approximately 12 volts D. C. so as to prevent sparking at the contact points I56 which are part of said control circuit. The control circuit I may draw its power from any suitable source such as a generator or battery. Fig. 17 shows a battery 292 as the power source for the control circuit I. Besides the earlier mentioned contact points I56, the control circuit I further includes a relay magnet 296 which is adapted to draw a blade 298 of the switch 290 against the resistance of a spring 299 into engagement with a contact 300 thereof which normally holds the blade 298 in contact with the other switch contact 302. The control circuit I includes also a foot operated switch 304 which is 'tation of the engaged clutch elements 228, 230

closed while the machine is in operation. The control circuit II includesv the double-throw switch 290 and two relay magnets 306 and 308 which may be alternately connected with a suitable source of 110 volts D. C. current upon engagement of the switch blade 298 with the contacts 300 and 302, respectively. Normally, the relay magnet 308 is energized due to the normal engagement of switch blade 298 with the contact 302, whereas the other relay magnet 308 is normally deenergized, as can be readily understood. Upon closing the control circuit I by a commutator bar 28 engaging contacts, I56, the switch blade 298 is drawn into engagement with contact 300 by the energized relay 296, and the control circuit II is then closed through the relay magnet 308. More particularly, the control circuit II is connected with the lines 30I of a 110 volts D. C. supply through the lead 3I0, switch blade 298, contact 300, lead 3I6, relay 308 and the leads 3I5 and 3I4. The manually operated switch 305 in one of the power lines 30! is closed when the machine is in operation. The energized relay 308 draws a normally open switch 3I8 closed, thereby closing the solenoid circuit IV through the following connections: leads 3 I4 and 3H, switch 3I8, lead 3I9, solenoid I54 and lead 32L The control circuit I is closed as long as the points I58 contact a conductive commutator bar 28. Therefore, when the points engage a mica separator 20, the control circuit I is opened,

and the switch blade 298 returns to normal contact with pole 302, thereby closing control circuit II through the relay 306 by way of the leads 3I2 and 3I3. The energized relay 306 closes a normally open switch 320 of the solenoid circuit III which comprises the leads 3I4 and 3, switch 328', lead 309, solenoid 238, a switch 322 (normally open but then held closed) and the leads 301 and 3I 0. The limit switch 322 is closed when its lever 323 is in engagement with a cam lug 324 of the table 34 as best shown in Fig. 4. The table is then in its home position in which the cutter I58 is separated from the commutator (see Figs. 2 and '7). When the solenoid circuit III is thus closed as indicated in heavy lines in Fig. 17, the one revolution clutch 228, 230 is engaged and the table 34 starts a reciprocation. The cam 324 releases the switch lever 323 shortly after the table 34 started on its reciprocation, whereupon switch 322 assumes its normal open position and interrupts the solenoid circuit III. The cam 324 is long enough to delay the opening of switch 322 until the one revolution clutch has turned suificiently to be held closed by arm 240. The cam 324 reengages the switch lever 323 and closes the switch 322 shortly before the table 34 completes one reciprocation. Of course, the solenoid circuit III is reopened after a concluded reciprocation of the table 34 by the double-throw switch 290 upon closing of the control circuit I, followingthe partial indexing of the armature by the stationary cam I88 and renewed contact of the points I56 with the next conductive commutator bar. It can now be understood that the solenoid circuits III and IV are alternately opened and closed, resulting in alternate mica undercutting operations and armature indexing operations.

Automatic stop F Referring more particularly to Figs. 1, 2 and 12 to 14 inclusive, a ratchet 330 is mounted on a stub shaft 332 which carries at its lower end a disc 334. Cooperating with the ratchet 330 is a spring-urged pawl 336 which is pivotally mounted at 338 on the table 34 and adapted to index the ratchet 336 the angular distance of one ratchet tooth 33! for each reciprocation of the table. There are as many ratchet teeth 33! as there are mica separators in a commutator so that the ratchet has completed one revolution after all mica separators have been undercut. The disc 334 is provided with a notch 346 which receives the upper end of a lock bar 342 when the machine is at rest. As more particularly shown in Fig. 1, this bar 342 is connected to a foot pedal 346 through a link 344. A collar 348 is mounted on bar 342 and is guided in a spring retainer 356 which is secured to the machine frame 36 and contains a compression spring 352. This spring 352 normally urges bar 342 into the illustrated uppermost position in Figs. 1, 13 and 14, in which the upper end of said bar projects into the notch 346. Mounted on suitable cross bars 354 of the machine frame 36 are the two switches 364 and 365, between which the link 344 passes. This link carries a collar 356 which operate simultaneously on the arms 358 of both switches 364, 365 and closes the same upon depression of the foot pedal 346. Thus in order to start the machine, the operator steps on the foot pedal 346, thereby not only closing the switches 364, 365 but also withdrawing bar 342 from registry with the notch 346 and permitting disc 334 and ratchet 336 to rotate. Of course,

the closing of the switches 364, 365 upon depres- 1 sion of the foot pedal 346 causes immediate closing of one of the solenoid circuits III or IV and ,the following alternate energization of both soleholds until all mica separators of a commutator are undercut. Some time will naturally elapse before the disc 334 and ratchet 336 are rotated suificiently to bring the notch 346 out of alignment with the bar 342 even though the table solenoid 236 should be the first to be energized prevent bar 342 from again registering with the notch 346 and thereby permit reopening of the normally open switches 364, 365 before the notch 346 has moved out of alignment with bar 342, the latter is immediately arrested in the illustrated depressed position in Fig. 12 by the arm 366 of a lever 362 which is pivotally mounted at 364 on top of the machine frame 36. This lever is arrested in the illustrated locking position in Fig. 12 by a stud 366 of a lever 368 which is pivotally mounted at 316 to the machine frame 36. When the machine is at rest, the lever 366 rests on lever 362 in the manner shown in Fig. 13. When the foot pedal 346 is depressed, gravity causes lever 362 to follow the descending bar 342 into the position shown in Fig. 12, and the stud 366 of lever 368 is snapped in place behind lever 362 by a tension spring 312. The'stud 366 locks lever 362 in the position shown in Fig. 12 against the compression of spring 352 (see Fig. 1). Lever 362 preferably keeps bar 342 depressed to such an extent that there isa clearance maintained between said bar and the bottom surface 314 of disc 334 so as to eliminate any friction between said disc and the bar 342 while the former is indexed. The ratchet disc 336 is further provided with a cam lug 316 which is angularly spaced from the notch 346 to such an extent that it will cooperate with lever 368 and rock the same clockwise sufiiciently to release lever 362 just when the notch 346 aligns with the bar 342. The

purpose for angularly spacing cam lug 316 from notch 346 is to have the cam lug 316 out of alignment with the lever 368 when the machine is in home position, i. e. when, bar 342 projects into the notch 346, so..as to permit lever 368 to descend on top of the ratchet disc 336 and lock lever "362 immediately upon renewed depression of the, foot pedal 346 for a restart of the machine. Of course, when the bar 342 moves into registry with the notch 346 after a complete revolution of disc 334, the switches 364, 365 are permitted to open and disconnect the electrical control devices from their power source.

Mode of operation Before starting the machine, the operator steps on the foot pedal to cause withdrawal of the movable center 58, and then aligns an armature with the chuck centers 58, H6, thereupon releasing the foot pedal. The machine is now ready for operation and the operator will next depress the foot pedal 346, thereby not only withdrawing bar 342 from locking engagement withthe disc 334, but also closing the switches 364, 365. The control circuits are connected with their'power sources and one of the solenoid circuits III and IV is immediately closed, depending on the location of the points I56 relative to a mica separator or a conductive commutator bar of the armature. The points I56 contact in most cases engages a commutator bar which causes closing of the solenoid circuit IV and consequent indexing of the armature until the next mica separator is contacted by said points. The double-throw switch 266 closesthe solenoid circuit III immediately after the opening of the circuit IV thereby causing one complete reciprocation of the table 34 in the earlier explained manner. Due to the explained electrical, con trol,'indexing operations alternate with under cutting operations until the last mica separator is undercut. "The notch 346 realigns then with the bar "342 which has been previously released by the cam 316, whereupon said bar reenters notch 346 andpermitsthe switches 364, .365 to reopen and break all connectionsbetween the electrical control devices and their power sources. The machine then comes to rest and theoperator depresses the foot pedal 66, in order to withdraw the center 58 fromthe armature shaft to the machine and deposition of a new. armature therein. ,Renewed depression of the other foot pedal 346 restarts the machine for operation on the newly deposited armature.

While the embodimentlof the present invention a herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. i

What is claimed is as follows:

1. A machine for undercutting the Insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means forproducing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means .for controlling the indexing means including a contact in alignment with the undercutting means for engaging the commutator and a circuit established by the engagement of the permit removal of the finished armature from contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, and means for causing a commutator bar to be engaged by the contact subsequent to an undercutting operation.

2. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the indexing means including a contact in alignment with the undercutting means for engaging the commutator and a circuit established by the engagement of the contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, and means responsive to relative bodily movement between the commutator supporting means and the undercutting means, the one away from the other, for causing a slight rotation of the commutator to move a bar thereof into position to be engaged by the contact whereby the power operated indexing means is started.

3. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the indexing means in cluding a contact in alignment with the undercutting means ior engaging the commutator and a circuit established by the engagement of the contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, means for causing a commutator bar to be engaged by the contact subsequent to an undercutting operation, and means functioning after a predetermined number of undercutting operations having been performed for rendering inoperative the means which produces relative bodily movement between the commutator supporting means and the separator undercutting means, and for interrupting an electrical circuit of the index controlling means.

4. A machine for undercutting the insulating separator of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the indexing means including a contact in alignment with the undercutting means for engaging the commutator and a circuit established by the engagement of the contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, means responsive to relative bodily movement between the commutator supporting means and the undercutting means, the one away from the other, for causing a slight rotation of the commutator to move a bar thereof into position to be engaged by the contact whereby the power operated indexing means is started, and means functioning after a predetermined number of undercutting operations having been performed for rendering inoperative the means which produces relative bodily movement between the commutator supporting means and the separator undercutting means, and for interrupting an electrical circuit of the index controlling means.

5. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, e ectrical means for controlling the indexing me ns including a contact in alignment with the undercutting means for engaging the commutator and a circuit established by the engagement of the contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, means for causing a commutator bar to be engaged by the contact subsequent to an undercutting operation, means functioning after a predetermined number of undercutting operations having been performed for rendering inoperative the means which produce relative bodily movement between the commutator supporting means and the separator undercutting means for interrupting an electrical circuit of the index controlling means, and for effecting the release of the commutator from its supporting means.

6. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the indexing means including a contact in alignment with the undercutting means for engaging the commutator and a circuit established by the engagement of the contact with a commutator bar to cause the commutator to be rotated until the bar is moved away from the contact, means responsive to relative bodily movement between the commutator supporting means and the undercutting means, the one away from the other, for causing a slight rotation of the commutator to move a bar thereof into position to be engaged by the contact whereby the power operated indexing means is started, means functioning after a predetermined number of undercutting operations having been performed for rendering inoperative the means which produce relative bodily movement between the commutator supporting means and the separator undercutting means and for interrupting an electrical circuit of the index controlling means, and for efiecting the release of the commutator from its supporting means.

7. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and the separator undercutting means, mechanical means for intermittently indexing the commutator to move the separators successively a predetermined angular distance to establish an electrical circuit, electrically controlled means for moving the separators into alignment with the undercutting means to open the circuit, and means for causing the machine to stop automatically after predetermined number of undercutting operations have been performed and for effecting the release of the commutatorfrom its supporting -means.

8. A machine for undercutting .the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, means for producing relative bodily movement between the commutator supporting means and :the separator undercutting means, mechanical determined angular distance and out of align ment with the undercutting means, electrical imeans operable after the operation of the mechanical means for controlling the indexing means to move the separator into alignment with the undercutting means, and means for rendering ineffective the electric means for con-trolling the indexing means, for stopping the machine and for effecting the release of the commutator from its supporting means.

9. A machine for undercutting the insulating separators of a commutator comprising, in com- :bination, means for supporting a commutator,

ated means for intermittently indexing'the commutator to move the separators successively into alignment with the undercutting means-electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means and engageable with the commutator, a circuit established in response to engagement of the contact with a commutator bar for causing the indexing means to operate until the contact is separated from the bar by rotation of the commutator, and a circuit established in response to the completion of the indexing operation for causing the reciprocating memberto operate and means responsive to movementof the reciproeating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact.

10. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means and engageable with the commutator, a

circuit established in response to engagement tof the'contact with a commutator bar for causing the indexing means to operate until the contact is separated from the bar by rotation of the commutator, and a circuit established in response to thecompletion of the idexing operation for causing the reciprocating member to operate :and means responsive to movement of the reciprocating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact, and means for interrupting both circuits automatically after predetermined number of undercutting operations have been performed.

11. A machine for undercutting the insulating separators of'a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting'means and the separator undercutting means, and including a one-revolution clutch for connecting a'source of mechanical power with the reciprocating memher, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the un-' dercutting means and engageable with the commutator, a circuit established inresponse to engagement of the, contact with a commutator bar for causing the indexing means to operate until the contact is separated from the bar by rota-" tion of the commutator, and a circuit including a solenoid energized in response to the completion ofthe indexing operation for causing the one-revolution clutch to be connected, and means responsive to movement of the reciprocating member subsequent .to the undercutting operation for causing the commutator to be turned slightly to cause a bar-thereof to move into position to be engaged by the contact.

12. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator,

means for undercutting'the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move theseparators successively into able with the commutator, a circuit including a solenoid established in response to engagement of thecontact with a commutator bar for causing the clutch to connect the source of power with the indexing means until the commutator has been turned so that the commutator bar is separated from the contact, a circuit established in responseto thecompletion of the indexing operation for causing the reciprocating member to operate, and means responsive to movement of the reciprocating member subsequent to the undercutting operation for causing the commutator tov be turned slightly-to cause a bar thereof to move: into position to-be engaged 'bythe contact.

13. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, and including a one-revolution clutch for connecting a source of mechanical power with the reciprocating member, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means and including a clutch for connecting a source of mechanical power with the commutator supporting means to rotate the same, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means and engageable with the commutator, a circuit including a solenoid established in response to engagement of the contact with a commutator bar for causing the clutch to connect the source of power with the indexing means until-the commutator has been turned so that the commutator bar is separated from the contact, a circuit including a solenoid energized in response to the completion of the indexing operation for causing the one-revolution clutch to be connected, and means responsive to movement of, the reciprocating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact.

14. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, and including a one-revolution clutch for connecting a source of mechanical power with the reciprocating memher, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means and engageable with the commutator, a circuit established in response to engagement of the contact with a commutator bar for causing the indexing means to operate until the contact is separated from the bar by rotation of the commutator, a circuit including a solenoid energized in response to the completion of the indexing operation for causing the one-revolution clutch to be connected, means responsive to movement of the reciprocating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact, and means for interrupting all circuits automatically after a predetermined number of undercutting operations have been performed.

15. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means, and including a clutch for connecting a source of mechanical power with the commutator supporting means to rotate the same, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means. and engageable with the commutator, a circuit including a solenoid established in response to engagement of the contact with a commutator bar for causing the clutch to connect the source of power with the indexing means until the commutator has been turned so that the commutator bar is separated from the contact, a circuit established in response to the completion of the indexing operation for causing the reciprocating member to operate and means responsive to movement of the reciprocating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact, and means for interrupting all circuits automatically after a predetermined number of undercutting operations have been performed.

16. A machine for undercutting the insulating separators of a commutator comprising, in combination, means for supporting a commutator, means for undercutting the insulating separators, power operated means including a reciprocating member for producing relative bodily movement between the commutator supporting means and the separator undercutting means, and including a one-revolution clutch for connecting a source of mechanical power with the reciprocating member, power operated means for intermittently indexing the commutator to move the separators successively into alignment with the undercutting means and including a clutch for connecting a source of mechanical power with the commutator supporting means to rotate the same, electrical means for controlling the reciprocating member and the indexing means and comprising a contact in alignment with the undercutting means and engageable with the commutator, a circuit including a solenoid established in response to engagement of the contact with a commutator bar for causingthe clutch to connect the source of power with the indexing means until the commutator has been turned so that the commutator bar is separated from the contact, a circuit including a solenoid energized in response to the completion of the indexing operation for causing the onerevolution clutch to be connected, means responsive to movement of the reciprocating member subsequent to the undercutting operation for causing the commutator to be turned slightly to cause a bar thereof to move into position to be engaged by the contact, and means for interrupting all circuits automatically after a predetermined number of undercutting operations have been performed.

1'7. A control system for a commutator separator undercutting machine having power means including a one-revolution clutch for effecting the reciprocation of a member which produces relative bodily movement between the commutator and a separator undercutting means, and having power means including a clutch for effecting indexing rotation of the commutator to move its insulating separators successively into alignment with the undercutting means, said control system comprising in combination, a circuit including a pair of aligned contacts adapted to be bridged by a commutator bar, said circuit being interrupted by engagement of the contacts with a separator, arelay switch controlled by the bridging of said pair of contacts, said switch having a contact movable into either of two positions, a solenoid for causing the indexing mechanism operating clutch to close and energize in response to movement of said relay contact into the position responding to the engagement of a commutator bar with said pair of aligned contacts, a solenoid for causing the one-revolution clutch to close and energize in response to movement of said relay contact into the position responding to the engagement of a commutator spacer with said pair of aligned contacts, and a mechanism operated by the machine for effecting engagement of the said pair of aligned contacts with another commutator bar subsequent to an undercutting operation,

18. A control system for a commutator separator undercutting machine having power means including aone-revolution clutch for effecting the reciprocation of a member which produces relative bodily movement between the commutator and a separator undercutting means and having power means including a clutch for effecting indexing rotation of the commutator to move its insulating separators successively into alignment with the undercutting means, said control systern comprising in combination, a circuit including a pair of aligned contacts adapted to be bridged by a commutator bar, said circuit being interrupted by engagement of the contacts with a separator, a relay switch controlled by the bridging of said pair of contacts, said switch having a contact movable into either of two positions, relay switches respectively energized in response to movement of said two-position contact into either of its contact making positions, solenoids energized, respectively, in response to the closing of said second-mentioned relay switches, one of said solenoids effecting the closing of the clutch which controls the indexing operation when the pair of aligned contacts is bridged by a commutator bar, and the other of said solenoids effecting the closing of the onerevolution clutch controlling the operation of the reciprocating member when the pair of aligned contacts is engaged with an insulating spacer, and a mechanism operated by the machine for eifecting engagement of the said pair of aligned contacts with another commutator bar subsequent to an undercutting operation.

19. A control system for a commutator separator undercutting machine having power means including a one-revolution clutch for effecting the reciprocation of a member which produces reiative bodily movement between the commutator and a separator undercutting means, and having power means including a clutch for effecting indexing rotation of the commutator to move its insulating separators successively into alignment with the undercutting means, said control system. comprising in combination, a circuit including a pair of aligned contacts adapted to be bridged by a commutator bar, said circuit being interrupted by engagement of the contacts with a separator, a relay switch controlled by the bridging of said pair of contacts, said switch having a contact movable into either of two positions, a solenoid for causing the indexing mechanism operating clutch to close and energize in response to movement of said relay contact into the position responding to the engagement of acommutator bar with said pair of aligned contacts, a solenoid for causing the one-revolution clutch to close and energize in response to movement of said relay contact into the position responding to the engagement of a commutator spacer with said pair of aligned contacts and a mechanism operated by the machine for effecting engagement of the said pair of aligned contacts with another commutator bar "subsequent to an undercutting operation, and

means for interrupting all circuits automatically after a predetermined number of undercutting operations have been performed.

20. A control system for a commutator separator undercutting machine having power means including a one-revolution clutch for effecting the reciprocation of a member which produces relative bodily movement between the commutator and a separator undercutting means and having power means including a clutch for effecting indexing rotation of the commutator to move its insulating separators successively into alignment with the undercutting means, said control system comprising in combination, a circuit including a pair of aligned contacts adapted to be bridged by a commutator bar said circuit being interrupted by engagement of the contacts with a separator, a relay switch controlled by the bridging of said pair of contacts, said switch having a contact movable into either of two positions, relay switches respectively energized in response to movement of said two-position contact into either of its contact making positions, solenoids energized, respectively, in response to the closing of said second-mentioned relay switches, one of said solenoids efiecting the closing of the clutch which controls the indexing operation when the pair of aligned contacts is bridged by a commutator bar, and the other of said solenoids efiecting the closing of the one-revolution clutch controlling the operation of the reciprocating member when the pair of aligned contacts is engaged with an insulating spacer, and a mechanism operated by the machine for effecting engagement of the said pair of aligned contacts with another commutator bar subsequent to an undercutting operation, and means for interrupting all circuits automatically after a predetermined number of undercutting operations have been performed.

21. A machine for undercutting the insulating separators of a commutator comprising, in combination; means for supporting the commutator; a rotary cutter; contacts pivotally supported above and in alignmentwith the cutter adapted to bear against the commutator; power operated means for periodically advancing the commutator when one of the separators is in alignment with the cutter and retracting it from the cutter; mechanical means for indexing the commutator a predetermined angular distance upon retraction of the commutator to move the undercut separator out of alignment with the contacts and move an adjacent'commutator bar beneath the contacts; electrical means operable after the contacts engage the bar to establish a circuit for causing the commutator to be rotated until the contacts en age another separator whereby said circuit is broken; and means for moving the contacts from the separator when the commutator is moved toward the cutter.

22. A machine for undercutting the insulating separators of a commutator comprising, in combination; means for supporting the commutator; a rotar cutter; contacts pivotally supported in alignment with the cutter and adapted to bear against the commutator; power operated means tfor periodically advancing the commutator past the cutter when the cutter is in alignment with a separator and retracting it from the cutter; means for moving the contacts from the commutator on movement of the commutator toward the cutter; indexing means for slightly turning the commutator on the return movement of the commutator so that the undercut separator will be out of alignment with the cutter and allow the contacts to engage a bar and establish a circuit; electrically controlled means operable on closing of said circuit for causing the indexing means to rotate the commutator until the contacts engage another separator whereby the circuit is opened; and means functioning after a predetermined number of undercutting operations have been performed upon the commutator for stopping the machine.

23. A machine for undercutting the insulators of a commutator comprising, in combination; means for supporting the commutator; a cutter; contacts pivotally supported in alignment with the cutter and adapted to establish an electrical circuit when in engagement with a bar of the commutator; electrical means operable when the circuit is established to rotate the commutator until the contacts engage an insulator whereby the circuit is opened; power means operable after the circuit is opened for moving the commutator past the cutter to undercut said separator and retracting it from the cutter; means for moving the contacts from the commutator as the com mutator approaches the cutter; means for slightly rotating the commutator near the end of the retracting movement whereby the contacts will engage another bar to establish the circuit for operating the electrical means; and means for automatically stopping the machine when all of the separators have been undercut.

LORA E. POOLE. 

